I'm looking for a cool physics experiment for my class project. Any ideas please?

Question

My demonstration has to be 12 minutes long

Answer 1

Here's a thought"

Get a solar cell and some wax.

Connect the solar cell to a resistive heating element that is impregnated in the wax. Make sure that the current is near but below the max current of the cell. Put the wax in an insulated vessel. with a removeable top.

Now you have created asolar energy system that will store energy in the daytime (sunlight) for use later (say at night for heating a home.

The heat of fusion of your wax can be observed empirically by measuring the energy from the solar cell that gets transferred to the wax to melt it. (V*I*time). The wax you buy at the hardware store is usually about 35 cal/gm.

Next, you want to demonstrate the useage of the stored energy. Using a beaker of water that will sit tightly over the opening of the wax container.

Then you can measure the rise in temperature of the water to simulate heating a home.

This can be small scale to make the point and then scale up to house dimensions in a presentation.

You can buy a 2.4 V 20 mA solar cell for 5 dollars. Buy four of them and connect in parallel.

Add resistors in parallel to have the equivalent of 37.5 ohm as your heating element and at full power you will be dissipating about 150 mW. This will melt a gram of wax in just over 3 minutes and store about 30 calories. Keep in mind that one cal will raise on gram of water 1 degree c.

Set it up so you have water from a fridge at about 45 to 50 degrees (so you get some help from the ambient warm air)
Then with a thermometer, use the wax as a heater to warm the water.

In your presentatin compare this to the energy needs of a one family house to heat for 8 hours.

Here's a link to help you make a compelling story


http://www.eia.doe.gov/kids/energyfacts/uses/residence.html


here's another

http://www.climatetechnology.gov/library/2003/tech-options/tech-options-2-3-3.pdf

enjoy

j

Answer 2

concentration on density... like in line with possibility you may have a tumbler of water, and pour an inch of oil into the cup, and then heavily drop nutrients coloring into the cup. it shows which products are greater and much less dense than others. i do those density projects each and every of the time. (you additionally can upload greater products including grapes, raisins, a coin. describe why those issues are in one in each and every of those place (they gained't all sink to the backside) and describe which products they're greater or much less dense than